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Structure from motion structure for motion: automatic recovery of camera motion and scene structure from two or more images. It is a self calibration technique and called automatic camera tracking or match moving. Unknowncameraviewpoints

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TF-IDF score is the product of these quantities: 0.03 × 4 = 0.12 The word is important if the TF-IDF score is large 某一特定文件內的高詞語頻率，以及該詞語 在整個文件集合中的低文件頻率，可以產生 出高權重的 TF-IDF 。因此， TF-IDF 傾向於過 濾掉常見的詞語，保留重要的詞語。

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Query expansion Large-scale image matching Better approach: use bag-of-words technique to find likely matches For each image, find the top M scoring other images, do detailed SIFT matching with those

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Outline 1. Introduction 2. System Design 3. Result 4. Conclusion

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Matching and reconstruction statics for the three sets

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Building Rome in a Day Rome, Italy. Reconstructed 150,000 in 21 hours on 496 machines Colosseum St. Peter’s Basilica Trevi Fountain

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San Marco Square San Marco Square and environs, Venice. 14,079 photos, out of an initial 250,000. Total reconstruction time: 3 days. Number of cores: 496.

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Outline 1. Introduction 2. System Design 3. Result 4. Conclusion

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Conclusion Our experimental results demonstrate that it is now possible to reconstruct cities consisting of 150K images in less than a day on a cluster with 500 compute cores. Large-scale image matching 3D models tml